1. Field of the Invention
In at least one aspect, the present invention relates methods and equipment for forming an over-molded component, and in particular, to methods and equipment for forming an over-molded component with regions that are difficult to access.
2. Background Art
Multishot molding is a type of injection molding process in which a plastic part having several different colors or several different resins is formed. For example, in two shot molding a plastic part is formed from two different materials. This process is easily automated and able to produce success parts such as buttons and gear wheels with a firm core yet a soft feel. Although multi-material molding is a relatively new molding technology in the United States, it has been popular in Europe for a number of years. Multishot molding is particularly useful for hard and soft combinations of resins, multicolored components, housing or connectors with seals or gaskets, grips and tactile applications, back-lit graphics, weatherproofing, and vibration reduction.
In the typical two shot method, a first resin is injected into the molding apparatus to form a pre-molded part. Next, a second unit injects a second resin onto the premolded part. Typically, the two shot process is automated to form articles having different combinations of resins or colors. Although the two shot process works well, problems occur when it is necessary to over-coat (i.e., over mold) isolated regions in the first resin with the second resin. Such isolated regions occur in a part such as a vehicle console panel when ridges in the part isolate a tray or other recess in the console.
Accordingly, there is a need for two shot molding processes in which isolated regions in a molded part can be overcoated with a second resin.